Activating Low Octane Ignition Curve

Discussion in 'Crazy-Awesome almost Dakar racers (950/990cc)' started by stephenws, Oct 25, 2008.

  1. stephenws

    stephenws Wishful Wanderer

    Joined:
    Jul 19, 2008
    Oddometer:
    58
    Location:
    Davenport, IA
    After putting 2100 miles on my new 2007 990 Adventure (all of them with 91-93 octane), I decided to put some 89 octane fuel in the tank and try the low octane ignition curve. After disconnecting the wires under the seat, I started up the bike. Right away, I noticed the idle rpm dropped from it's normal steady 1500rpm to a variable 1200 to 1300rpm. After about five minutes of idling, the FI light came on and indicated a 18 blink code (lambda probe for front cylinder). I then shut down the engine and reconnected the ignition curve wires. Upon restarting, everything was back to normal.

    Has anyone else experienced this? One of the reasons I bought the bike was because of it's ability to adapt to various octane levels. In rural Iowa, most gas stations don't offer premium 91 to 93 octane gas - 89 octane with 10% ethanol is everywhere though

    Any thoughts on what might be happening? I'd really like to be able to use the 89 octane fuel.

    Thank you.
    #1
  2. Agave

    Agave El Corazón

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    Did you make sure the connector ends weren't making contact with any metal? Try taping them up...
    #2
  3. Englishmatt

    Englishmatt Been here awhile

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    no,

    I purchased the low octane switch from KTM hutt and it works great, just a switch on the handle bars and I don't have to mess with the connector under the seat.

    now, i've run 89 in it from time to time without making the switch and noticed no real change.

    before I got my switch I did disconnect the connector under the seat, but no FI light warnings....

    just my .2c.
    #3
  4. stephenws

    stephenws Wishful Wanderer

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    Thanks for the input. Yes, I did have the connectors insulated from contact with any metal. I temporarily used some short sections of plastic tubing.
    #4
  5. sheikyabooty

    sheikyabooty Adventurer

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    Silly Noob question I know, but why?

    As I am taking this puppy (990 adv s) around the world and am sure to encounter some less than favourable fuel is it wise that I look into this?
    #5
  6. Pom

    Pom Old fart on big bike

    Joined:
    Nov 20, 2007
    Oddometer:
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    Location:
    The Back of Beyond, SW Queensland, Australia
    I live in outback Oz and the fuel out here is crap - but if I mess with the low octane switch the bike plays up, apparently they all do.
    A friend out here has brought a new LC8 each year (he has way too much money) and has never bothered with the switch, he hasn't had any problems.
    I have covered 21,000km from new in Nov last year with various fuel grades always set to high octane with no problems.
    My advice would be just ride it and don't worry about it.
    Pom
    #6
  7. Agave

    Agave El Corazón

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    Portland,OR
    I am far from a mechanic but it was my understanding that without a knock sensor which the LC8's dont have, the engine can't compensate when pinging occurs. Changing the ignition curve for lower octane fuel would be essential to avoid engine damage... Not true??
    #7
  8. irelage

    irelage Been here awhile

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    Location:
    Sanford, NC
    Is it possible to just run 87 octane in the 990 without causing damage? Is anyone doing that? It sure would be great if you could.
    #8
  9. tahoeacr

    tahoeacr Long timer

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    I know some poeple that have, but I don't know for sure if they where at sea level like you. I have installed a knock sensor on my bike and I can read the ignition timing. Only problem is I haven't figured out how to ride WFO with my lap top in my hand:rofl . Next dyno session I will report back as to how much that wire retards the timing. My personal feeling is the ignition map can't be that advanced without a knock sensor. The stock ignition map does have 55 degrees advanced in areas like 5K with 20% throttle.
    #9
  10. gerbois

    gerbois Adventurer

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    STEPHENWS,

    I had the same "adventure" with my 990 2007, when 2500 km in the meter. The witness FI began to flash when i disconnect wires, and stop when I re-linked it. I had no time to understand code... :eek1

    But everything seems normal since this time... :ricky

    But, now, I always add octane booster, even in 93 gas. KTM ask 95.:1drink The engine seems to work more gently, maybe this is just in my head?:norton
    #10
  11. stephenws

    stephenws Wishful Wanderer

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    Jul 19, 2008
    Oddometer:
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    Location:
    Davenport, IA
    Thanks for all the information.

    I put about 100 miles on the bike today using the 89 octane, with the ignition curve wires connected, with no apparent problems.

    If I don't hear any pinging does that mean no damage is being done, or isn't it that obvious?

    I think I'll check into carrying some octane booster with me, just in case.
    #11
  12. gerbois

    gerbois Adventurer

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    Canada
    I dont think it's easy to discern problem by running.:chace It is when you try with the good indication of octane it is possible to identify a little more suppleness.

    Its just my perceptions...:stoned
    #12
  13. KatoomDownUnder

    KatoomDownUnder Safer off a horse than on

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    Pinging / knocking can be easily noticed especially when the motor is under load with crap fuel, it really does make a knocking sound. My old 05 Dakar used to do it all the time when I ran low octane fuel, as most fuel is Australia is. :patch
    #13
  14. Vicks

    Vicks gets stuck in sand

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    while on a 3,000+ kms ride, i came across situations where i had to tankup with non 95 Octane gas. First few times i disconnected the under-seat connector to change the ignition curve. We were riding 2-up, fully loaded with Gobis n stuff. I found absolutely no change at all, in the idle speed and the performance.

    The last 2 tank fulls of low octane gas, i didn;t even bother disconnecting the thing and she ran as usual. Bike has done 6,000kms and i have been commuting for approx 500kms since then, with no abnormalities.
    #14
  15. LC8TY

    LC8TY must......find.......fuel

    Joined:
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    was Kununurra, now Carnarvon, Australia
    I'd be more worried about not getting replacement fuel pump filters for the 990 than the low octain switch on a RTW trip. Cary some spares!

    My 950 did over 20,000 ks on crappy outback fuel and I didn't activate the low octain once. I did eventually install a switch for it but still didn't use it much for almost another 10,000 ks. No knocking, no problems.
    #15
  16. FastEddieB

    FastEddieB Been here awhile

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    Location:
    Mineral Bluff, GA
    FWIW, I installed a push/pull switch I had laying around, routing the wires to the "glovebox":

    [​IMG]

    On my 2005 950, I've been running regular for well over a year, with the wires "disconnected" and no issues at all.

    Of course, I'm carbureted. I don't notice and real change in power, performance, idle or smoothness. I'm just doing it to save money on gas, and in the twisties and offroad the power is still more than andequate.

    But That's Just Me™!
    #16
  17. erappaport

    erappaport pray for rain

    Joined:
    Jun 23, 2004
    Oddometer:
    300
    Location:
    Maine
    Anybody know if the octane rating system referred to in the KTM manual is the same as we use in the US, or is it a european standard? The book recommends disconnecting the wires when using fuel below 95 "ROZ". I don't recall seeing that acronym in the states, nor have I seen pump fuel above 93, except at an airport.
    #17
  18. jsrider

    jsrider Long timer

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    3,495
    It's European. Their 95 is approximately equivalent to our 91.
    #18
  19. dezracer

    dezracer Been here awhile

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    Location:
    Las Vegas,NV.
    Its normal. MOST 990s throw the code when the wires are disconnected.
    #19
  20. turkish

    turkish Long timer

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    Gone fishin
    My bike is a '03 950 and I never needed to use the low octane mode in the states. However, there's some really punky fuel down here in south america. My bike detonates/pings with the wires connected with Bolivian fuel which is 85 octane.

    I do notice less power and less fuel efficiency, but I'm not sure whether that's due to the "switch", the punky fuel or the altitude.
    #20